$A$ metal detector works on the principle of:

The use of eddy currents is done in the following,except:

What should be the resistivity of materials used for electromagnets,and why?

The core of any transformer is laminated so as to

Consider a metallic pipe with an inner radius of $1 \ cm$. If a cylindrical bar magnet of radius $0.8 \ cm$ is dropped through the pipe,it takes more time to come down than it takes for a similar unmagnetised cylindrical iron bar dropped through the metallic pipe. Explain.

Eddy currents are produced when